A Biologist Is Looking at Human Muscle Fibers Under the Microscope.Which

Multiple Choice

A biologist is looking at human muscle fibers under the microscope.Which criterion should the biologist use to distinguish between cardiac and smooth muscle fibers?

A) Number of cell nuclei
B) Presence or absence of a sarcoplasmic reticulum
C) Presence or absence of regular arrays of thick and thin filaments
D) Presence or absence of actin and myosin
E) Presence or absence of gap junctions